Ryall debunked suggestions he and the "brat packers", which included Conservation Minister Nick Smith and former minister Roger Sowry, worked as a group.

In fact, while they remained friends, they never agreed, Ryall said.

"It's always two-two on any issue."

Ryall said in the early days he had had a meal with the formidable Muldoon, but the conversation had quickly dried up.

After finishing their meal in silence for 15 minutes, Muldoon stood up and declared "that was really good, let's do it again sometime".

Ryall also recalled as health minister visiting an endoscopy ward. He had wondered why there were gasps of surprise from the staff after he washed his hand in what he thought was sanitising liquid – but turned out to be lubricating gel.

Ranked No 6 in Cabinet, Ryall, 50, was the highest-profile retirement among the 16 National MPs who either left or are retiring.

In recognition of his long service, Ryall was given the final valedictory speech before the House rises tomorrow for the election.